graypolarplot - Polar 2D plot of a surface using colors

Calling Sequence

graypolarplot(theta,rho,z,[strf,rect])

Parameters

• rho : a vector with size n1, the discretization of the radius
• theta : a vector with size n2, the discretization of the the angle.
• z : real matrix of size (n1,n2). z(i,j) is the value of the surface at the point (rho(i),theta(j)).
• strf : is a string of length 3 "xy0".
• The default is
• x : controls the display of captions.
• x=0 : no captions.
• x=1 : captions are displayed. They are given by the optional argument leg.
• y : controls the computation of the frame.
• y=0 : the current boundaries (set by a previous call to another high level plotting function) are used. Useful when superposing multiple plots.
• y=1 : the optional argument rect is used to specify the boundaries of the plot.
• y=2 : the boundaries of the plot are computed using min and max values of x and y.
• y=3 : like y=1 but produces isoview scaling.
• y=4 : like y=2 but produces isoview scaling.
• y=5 : like y=1 but plot2d can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.
• y=6 : like y=2 but plot2d can change the boundaries of the plot and the ticks of the axes to produce pretty graduations. When the zoom button is activated, this mode is used.
• y=7 : like y=5 but the scale of the new plot is merged with the current scale.
• y=8 : like y=6 but the scale of the new plot is merged with the current scale.
• leg : a string. It is used when the first character x of argument strf is 1. leg has the form "leg1@leg2@...." where leg1, leg2, etc. are respectively the captions of the first curve, of the second curve, etc. The default is " ".
• rect : This argument is used when the second character y of argument strf is 1, 3 or 5. It is a row vector of size 4 and gives the dimension of the frame: rect=[xmin,ymin,xmax,ymax].

Description

Takes a 2D plot of the surface given by z on a polar coordinate grid defined by rho and theta. Each grid region if filled with a gray or color level depending on the average value of z on the corners of the grid.

Examples

  rho=1:0.1:4;theta=(0:0.02:1)*2*%pi;
  z=30+round(theta'*(1+rho^2));
  xset('colormap',hotcolormap(128))
  xset('background',xget('white'))
  xbasc();graypolarplot(theta,rho,z)